Firefighters were called to reports of a flooding on Whitechapel Road in Whitechapel.
A building under refurbishment was flooded to a depth of around two metres and the basement of an adjoining property was also affected by minor flooding. There were no reports of any injuries.
Station Commander Paul Eastland, who was at the scene said: "Around 120 construction workers were evacuated from the site and road closures were put in place whilst crews worked to make the scene safe.
"Crews used a high volume pumping unit (HVP) to remove the water to a main drain."
The Brigade was called at 0748 and the incident was over for firefighters by 1328. Fire crews from Bethnal Green, Shadwell and surrounding fire stations attended the scene.